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Pre-Puched?

Roy25101

Active Member
So it's said "it is better to remain quiet and thought a fool than to open my mouth and remove all doubt". Well, here it goes. I just started on the VS of the -14 and my understanding was that many of the parts were now pre-punched to size and no longer required drill to size. I see the parts ending in PP but the instructions are still requiring the VS skin to be attached, all #40 holes drilled, all parts disassembled, and deburred.

I just thought I would ask before diving in. Thanks in advance.....
 
Most areas where match drilling is needed will be specifically called out in the plans. You’ll find very little of that in the empennage after you complete the VS, the VS is comprised mostly from parts of earlier kits.
 
My thinking was that “pre-punched” meant punched slightly under size. “Match drilled” meant drilled to correct size. I might be wrong about that. On my pre-punched kit parts, I used a piloted reamer, in assembly, to open the holes up to final size. Reamed holes are perfectly round, and the reamer leaves very little burr.
 
My thinking was that “pre-punched” meant punched slightly under size. “Match drilled” meant drilled to correct size. I might be wrong about that. On my pre-punched kit parts, I used a piloted reamer, in assembly, to open the holes up to final size. Reamed holes are perfectly round, and the reamer leaves very little burr.

My understanding is that "pre-punched" means there are holes there for you, usually undersized. Whether or not they're final sized is up to the piece itself. Most of the 14-specific parts are "final-sized pre-punched" with the 10-specific parts in both "pre-punched" and "final-sized pre-punched" state until the transition to offering only final-sized holes is complete.

"Match drilling" is a completely separate operation that involves drilling a new hole in one or more parts to mate up (match) with another part. Sometimes it's a final-sized match-drill, sometimes it's an under-sized match-drill that gets final-size drilled later.

no matter how you get there, your parts will all be "final-sized" by the time you're ready to dimple and rivet.

I'm building a -10 but here is how I see it:
- 000 prefix (?), it's probably a 14-specific part and final-sized pre-punched
- 10 prefix, it's probably a 10-originating part (except for variations that the 14 gets in the wing) and could go either way depending on DOM.
- 6,7,8,9 prefix, it's designed and spec'd in other models and will (usually) come pre-punched but not final-sized.
- manufactured pieces (angle stock, tubing stock, j-channel), you'll be match drilling.
 
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